The Drug Abuse Basic Research Center in the Department of Pharmacology of The University of Michigan is composed of established investigators who have independent but interrelated interests in problems related to drug abuse. Studies in the monkey colony will continue to be concerned with the development of physical dependence on new analgesic agents, to morphine antagonists and to compounds which have mixed agonist-antagonist properties. These new drugs will also be tested for their ability to sustain self-administration by rhesus monkeys. The reinforcing properties of a variety of centrally acting drugs will continue to be investigated, in studies which will be conducted in the newly completed, computer-controlled drug administration facility. A variety of biochemical studies will be concerned with the effects of drugs of abuse upon both the concentration and the rate of turnover of neurohumoral transmitters, including norepinephrine, acetylcholine, dopamine and serotonin. Metabolically active processes, which are responsible for the cellular transport of narcotic drugs into leukocytes and into synaptosomes, will receive continuing investigation. A variety of chemical and surgical manipulations of the central nervous system will be employed to modify the manifestations of morphine abstinence in the rhesus monkey.